Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757317Ab3DXQm0 (ORCPT ); Wed, 24 Apr 2013 12:42:26 -0400 Received: from mail-pd0-f174.google.com ([209.85.192.174]:51076 "EHLO mail-pd0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755277Ab3DXQmY (ORCPT ); Wed, 24 Apr 2013 12:42:24 -0400 Message-ID: <51780B6B.1040205@linaro.org> Date: Wed, 24 Apr 2013 09:42:19 -0700 From: John Stultz User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130329 Thunderbird/17.0.5 MIME-Version: 1.0 To: Kay Sievers CC: Alexander Holler , LKML , Feng Tang , Jason Gunthorpe Subject: Re: CONFIG_RTC_HCTOSYS lost on x86 with ALWAYS_USE_PERSISTENT_CLOCK changes? References: <517746E4.908@linaro.org> <51774F44.2060704@linaro.org> <517769A9.5060308@ahsoftware.de> <51780348.6090202@linaro.org> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1425 Lines: 32 On 04/24/2013 09:32 AM, Kay Sievers wrote: > On Wed, Apr 24, 2013 at 6:07 PM, John Stultz wrote: > >> So summarizing the above, because as much as I'm aware, its always been >> redundant and unnecessary on x86. Thus being able at build time to mark it >> as unnecessary was attractive, since it reduced the code paths running at >> suspend/resume. >> >> That said, Kay's concerns about userland implications (basically the >> userland side effects of SYSTOHC being enabled) give me pause, so I may >> revert the HAS_PERSISTENT_CLOCK on x86 change. > Thanks a lot for all the missing details! > > No, I think that all makes too much sense to revert it. Let's just > find a way to solve it properly. I don't think it is of any pressing > importance to keep the old behaviour, if we can still provide the > functionality today. So some compile time optimizations for code that likely needs to be reworked anyway aren't worth the risk of breaking userland to me. Let me pull these out (on the kernel side, the same code paths will run, we just avoid some extra checks) so the hctosys flag doesn't change in distro configs that expect it. thanks -john -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/